The invention relates generally to a yarn treatment chamber for the thermal treatment of a running yarn. The invention relates more particularly to a yarn treatment chamber for the thermal treatment of a running yarn, with a centre zone, in which a hot, gaseous or vaporous medium under pressure acts on the yarn, and end zones arranged on both sides of the centre zone, in which a cooling, gaseous medium is active, the end zones each having a yarn inlet opening or a yarn outlet opening with a yarn sluice, which, in the operating state in conjunction with the running yarn, seals the associated end zone and therefore the yarn treatment chamber
It is known in the textile industry to subject yarns, in particular after twisting or cabling, to a thermal treatment in a yarn treatment device and to therefore achieve a significant improvement in the yarn quality. A thermal treatment of this type does not only stabilise the state of the yarns after twisting or cabling, but also frees the yarns, in the process, from inner torsional forces. A thermal treatment of this type also often brings about an increase in volume of the yarns by shrink bulking.
Numerous patent applications, in which different yarn treatment devices are described, are known in the patent literature in connection with the thermal treatment of yarns. For example, it is proposed in various patent applications that a so-called yarn treatment chamber, with which a thermal setting can be carried out on the running yarn, is to be arranged in each case in the region of the workstations of twisters.
Yarn treatment chambers of this type, which are described in relative detail, for example, in European Patent Document EP 1 348 785 A1 or German Patent Document DE 103 48 278 A1, generally have a vertically arranged thermal treatment section with yarn inlet or yarn outlet openings opposing one another and arranged at the end.
In other words, the known yarn treatment chambers in each case have a centre zone, into which a hot, gaseous or vaporous treatment medium under pressure is blown, as well as end zones which are arranged on both sides of this centre zone and are acted on, in each case, with a cooling, gaseous medium, for example compressed air. The yarn inlet or yarn outlet opening arranged in the region of the end zones is in each case equipped with a sealing device, which seals the yarn treatment chamber from the environment. Sealing devices of this type are important components of yarn treatment chambers of this type as, on the one hand, efficient sealing has to be ensured by the yarn running through during operation and, on the other hand, the friction of the yarn running through should be as low as possible.
Even if there has been success with the known yarn treatment chambers in making the setting process of yarns relatively economical and efficient, there is still certainly potential for improvement in these yarn treatment chambers, in particular with regard to the arrangement of their yarn inlet opening and the configuration of their sealing devices. In other words, in the known yarn treatment chambers, the treatment section required for proper thermal treatment is relatively long, which, in conjunction with the vertical arrangement of the treatment section, leads to the upper yarn sluice arranged in the region of the yarn inlet opening generally being at a height of 2.5 m to 3.5 m and therefore being difficult for the operating staff to reach. In practice this means that the operating staff, if any work is necessary in the region of the upper yarn sluice, have to use an additional aid, for example a ladder or a comparable stepping assistance.
Consequently, with these yarn treatment chambers, both during maintenance work and also during the threading of a yarn, for example after a thread break or a feed material change, the operating staff always have to work with climbing assistance, which is laborious, time-consuming and not without danger when the textile machine is running.
Even if the known yarn treatment chambers are certainly configured in a comparable manner with regard to their thermal treatment section, these yarn treatment chambers differ, sometimes considerably, in particular with regard to their sealing devices, the so-called yarn sluices, arranged at the yarn inlet or yarn outlet openings.
The yarn treatment chamber described in European Patent Document EP 1 348 785 A1, for example, has sealing devices at the end of its thermal treatment section arranged in a linear orientation, which in each case consist of drivable outer sluice rollers and inner sealing rollers, the sealing rollers in turn being equipped with a resilient plastics material ring. The running yarn, when passing the sealing devices, slightly deforms the resilient plastics material rings, which leads to a proper sealing function. The plastics material rings of the sealing rollers are, however, very wear-sensitive so the relatively short service life of plastics material rings of this type requires short maintenance intervals of the yarn treatment chambers. Short maintenance intervals, however, as a rule often have a very negative effect on the overall efficiency of the textile machines equipped with yarn treatment chambers of this type. A comparable yarn treatment chamber is described in German Patent Document DE 103 48 278 A1, in other words, a yarn treatment chamber, in which the thermal treatment section formed from a centre zone and two end zones also has a linear orientation and in which a respective sealing device acting as a yarn sluice is arranged at the end in the region of the yarn inlet or its yarn outlet opening. The yarn sluice is, in this case, equipped with wear-resistant yarn guide elements. In other words, the yarn sluice either has two identical yarn guide elements, which are, in each case, configured in a semi-circular manner and which are pressed against one another by a spring element and, in the region of a common centre longitudinal axis, have recesses forming a yarn guide channel, or the yarn guide elements of the yarn sluice are configured such that one of the yarn guide elements is rotatably mounted in the manner of a revolver magazine and has a plurality of yarn guide channel recesses of different sizes.
The yarn sluices of the yarn treatment chambers known from German Patent Document DE 103 48 278 A1 are very wear-resistant, but yarn sluices of this type are problematical because of the often somewhat difficult adaptation of the cross section of their yarn guide channel to the respective thickness of the yarn.
A yarn treatment chamber for the thermal treatment of a running yarn is also described in the subsequently published German Patent Document DE 10 2010 022 211, in which the thermal treatment section has a linear orientation and, accordingly, the yarn inlet opening or the associated yarn sluice is arranged really high and is difficult to access for the operating staff. A respective yarn sluice, the yarn guide elements of which form a yarn guide channel, which is sealed by the running yarn in the operating state, is also arranged in this yarn treatment chamber in the region of the yarn inlet opening and the yarn outlet opening. For adaptation to the average thickness of the running yarn, at least one of the yarn guide elements of the yarn sluice can be positioned steplessly in various positions.
The yarn sluices also in each case have a sealing element, which rests on the yarn guide elements, extends along the yarn guide channel and reacts resiliently to defects in the running yarn. In other words, the sealing element of the yarn sluice, in conjunction with the associated yarn guide elements, ensures a proper seal of the yarn guide chamber relative to the atmosphere and therefore allows good thermal treatment of a running yarn in the yarn treatment chamber.